Download Chapt07 Lecture 13ed Pt 3

Human Biology
Sylvia S. Mader
Michael Windelspecht
Chapter 7
Lymphatic System
and Immunity
Lecture Outline
Part 3
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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7.4 Adaptive Immune Defenses
What do the specific defenses
include?
• Third line of defense
– Helps protect us against ________ pathogens
when nonspecific defenses fail
– Helps protect us against cancer
– Depends on the action of B and T cells
(remember that these are lymphocytes)
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7.4 Adaptive Immune Defenses
What are the types of B and T
cells?
• B cells produce plasma cells and memory
cells.
– ___________ produce specific antibodies.
– ___________ are ready to produce
antibodies in the future.
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7.4 Adaptive Immune Defenses
What are the types of B and T
cells?
• T cells regulate immune response;
produce various types of T cells.
– Cytotoxic T (Tc) cells kill ____________
and _______ cells.
– Helper T (TH) cells regulate immunity.
– Memory T (Tc and TH) cells are ready to kill
in the ________.
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7.4 Adaptive Immune Defenses
What are the types of B and T cells?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
memory
B cell
B cell
antibody
Antibodymediated
immunity
plasma
cell
BCR
APC
antigen
TCR
memory
TH cell
Adaptive
defenses
TH cell
activated
TH cell
activated
TC cell
Cellmediated
immunity
antigen
memory
TC cell
virus-infected
cell
TCcell TCR
Figure 7.10 Overview of adaptive immune defenses.
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7.4 Adaptive Immune Defenses
What are the characteristics of
B cells?
• _______________ immunity against pathogens
• Produced and mature in bone marrow
• Directly _________________ and then undergo
clonal selection
• Clonal expansion produces antibody-secreting
plasma cells as well as memory B cells
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7.4 Adaptive Immune Defenses
Third line of defense: Antibodymediated immunity by B cells
• Each B cell has a unique receptor called a BCR
that binds a specific antigen.
• This binding and cytokines secreted by helper T
cells result in clonal expansion in which this B
cell makes copies of itself.
• Most of the cells produced are ____________
that secrete antibodies .
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7.4 Adaptive Immune Defenses
Third line of defense: Antibodymediated immunity by B cells
• Other cells become memory cells which result in
long-term immunity.
• After an infection has passed, plasma cells
undergo ___________ (programmed cell death)
leaving memory cells.
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7.4 Adaptive Immune Defenses
Antibody-mediated immunity by B cells
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
antigen
B cell
antigens
cytokines
from T cells
B-cell
receptor
(BCR)
Plasma cells
Memory B cells
a. Activation: When a B cell receptor binds to an antigen
activation occurs.
b. Clonal expansion – During clonal expansion, cytokines secreted by
helper T cells stimulate B cells to clone mostly into plasma cells or memory cells.
Apoptosis
c. Apoptosis – Apoptosis, or programmed cell death, occurs to plasma cells
left in the system after the infection has passed.
Figure 7.11 Antibody-mediated immunity, or
the clonal selection model for B cells.
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7.4 Adaptive Immune Defenses
Structure of antibodies
• The basic unit that composes antibody
molecules is a ____________ protein.
• The trunk of the Y is a constant region that
determines the class of the antibody.
• The ends of the arms (Y) are the variable
regions where specific antigens bind.
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7.4 Adaptive Immune Defenses
Structure of antibodies
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
antigen-binding
sites
antigen
Antigen binds
to binding site.
light
chain
Shape of antigen fits
shape of binding site.
C
C
heavy
chain
C = constant
V = variable
a.
b.
Figure 7.12 The structure of an antibody.
b: Courtesy Dr. Arthur J. Olson, Scripps Institute
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7.4 Adaptive Immune Defenses
What are the 5 classes of
antibodies?
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7.4 Adaptive Immune Defenses
How do we make monoclonal
antibodies?
• We make monoclonal antibodies (derived from
plasma cells that originated from the same B
cell) in glassware outside the body (in vitro).
• This is done through fusion of plasma cells with
myeloma cells that allow them to divide
indefinitely.
• This fusion results in a cell called a hybridoma.
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7.4 Adaptive Immune Defenses
How do we make monoclonal
antibodies?
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
antibody
plasmacell
antigen
hybridomacell
cancerous
myelomacell
monoclonal
antibody
Figure 7.13 The production of
monoclonal antibodies.
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